A programmable logic controller executes an SFC program including a plurality of blocks, each including a step indicating an operation output and a transition indicating a transition condition. The programmable logic controller includes an SFC device data collecting unit for collecting device data of a device included in an active step for each scan at the time when the SFC program is executed, an SFC device data storing unit for storing the data collected by the SFC device data collecting unit, and an SFC device data outputting unit for outputting the data stored in the SFC device data storing unit to a memory card as a file for each of the steps or the blocks.

A programmable logic controller executes an SFC program including a plurality of blocks, each including a step indicating an operation output and a transition indicating a transition condition. The programmable logic controller includes an SFC device data collecting unit for collecting device data of a device included in an active step for each scan at the time when the SFC program is executed, an SFC device data storing unit for storing the data collected by the SFC device data collecting unit and an SFC device data outputting unit for outputting the data stored in the SFC device data storing unit to a memory card as a file for each of the steps or the blocks.

A monitoring device for a programmable controller includes: a display portion configured to display, on a display, a step that is being executed by the programmable controller among a plurality of steps in such a manner that the step can be distinguished from the other steps; a receiving portion configured to receive selection of a step serving as an initial point of reactivation in a case where a facility stops during a continuous operation by the programmable controller; and a change instruction generation portion configured to generate an instruction to the programmable controller so as to cause the programmable controller to restart execution of control processes from the step received by the receiving portion at the time of the reactivation.